Laserfiche WebLink
Supplement to RP 1604 -- p. 5 <br /> Page 4 <br /> Insert the following material after the first sentence of <br /> subsection 3 . 2 . 2 . 4 [formerly 3 . 2 . 41 : <br /> During removal of liquids or residues from a tank it is <br /> likely that air will enter the tank, and may bring the <br /> tank atmosphere into the flammable range. Extra care <br /> should be taken during removal operations. For a complete <br /> description of safety precautions, refer to API <br /> Publication 2015. <br /> Page 5 <br /> Change "SECTION 4 -- REMOVAL OF UNDERGROUND TANKS" to <br /> "Section 3 . 3 Removal of Underground Tanks, " and renumber the <br /> subsections accordingly. <br /> Change the title of subsection 114 . 2 Purging" to subsection <br /> 113 . 3 . 2 . 1 Purging and Inerting. " <br /> Delete the subsection 3 . 3 . 2 . 1 [formerly 4 . 2 . 1] and substitute <br /> the following: <br /> 3 . 3 . 2. 1 [formerly 4 . 2 . 1] "Purging" is the removal of <br /> flammable vapors from a tank so as to deprive a potential <br /> fire of any source of fuel. "Inerting" is the <br /> displacement of oxygen from a tank (and the incidental <br /> removal of some vapors) to deprive a potential fire from a <br /> source of oxygen. A tank may be inerted by one of the <br /> methods described below in subsections 3 . 2 . 2 . 3 [formerly <br /> 4 . 2 . 4] or 3 . 2 . 2 . 4 [formerly 4 . 2 . 4] . A tank may be purged <br /> by one of the methods described below in subsections <br /> 3 . 2 . 2 . 5 [formerly 4 .2 . 5] , 3 .2 . 2 . 6 [formerly 4 . 2 . 6] , or <br /> 3 . 2 . 2 . 7 [formerly 4 . 2 . 7] . It is important to recognize <br /> that a tank may continue to be a source of flammable <br /> vapors even after following one of these procedures. For <br /> this reason, caution must always be exercised when <br /> handling or working around tanks that have stored <br /> flammable or combustible liquids. Before initiating work <br /> in the tank area or on the tank, a combustible gas <br /> indicator should be used to assess vapor concentrations in <br /> the tank and work area. <br /> Delete the subsection 3 . 3 . 2 .2 [formerly 4 . 2 . 2] and substitute <br /> the following: <br /> Both purging and inerting cause the displacement of vapors <br /> from the tank. All vapors should be vented from the tank <br /> at a minimum height of 12 feet above grade and 3 feet <br /> • <br />